This seem to happen (at least) in Kontact: e.g. when I move (internally within Kontact) from akregator to contacts then App Menu fails to remove the old set of buttons (from akregator) and simply add the new ones (from contact). Then, if I try to click on one of the old buttons, plasma crashes.
I can confirm this behaviour on Arch Linux.
Can you provide a backtrace, please.
It seemed harder to get it to crash when plasmashell was outputting debug information on the terminal but i got it to crash :) The output of Plasmashell looks like this: https://paste.kde.org/psjdwtfw2 And the crash report from Dr. konqi looks like this: https://paste.kde.org/pqghie4vv I have made a video on how to reproduce: https://youtu.be/Xo2hPO8SjXg
Thanks for the video. I'll try with Kontact, then. Your backtrace unfortunately lacks debug symbols but I think when I install Kontact I should be able to reproduce it myself :)
I can reproduce. Thread 1 (Thread 0x7f50fa70b8c0 (LWP 15513)): [KCrash Handler] #6 0x00007f50f618c060 in QAction::menu() const () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5 #7 0x00007f4ffe1127d1 in AppMenuApplet::createMenu(int) const () from /usr/lib/x86_64-linux-gnu/qt5/plugins/plasma/applets/plasma_applet_appmenu.so #8 0x00007f4ffe112886 in AppMenuApplet::trigger(QQuickItem*, int) () from /usr/lib/x86_64-linux-gnu/qt5/plugins/plasma/applets/plasma_applet_appmenu.so #9 0x00007f4ffe1146e4 in AppMenuApplet::qt_static_metacall(QObject*, QMetaObject::Call, int, void**) () from /usr/lib/x86_64-linux-gnu/qt5/plugins/plasma/applets/plasma_applet_appmenu.so